Platelet-rich Plasma Formulations Research Articles

Efficacy of Platelet-Rich Plasma versus Mesotherapy with Recombinant Growth Factors and Stem Cell-Conditioned Media in Androgenetic Alopecia: A Retrospective Study

Introduction: Androgenetic alopecia (AGA) is the most common type of hair loss. Platelet-rich plasma (PRP) and mesotherapy (MZT) injections of various solutions fortified with growth factors are popular treatment options for AGA. The aim of this study was to compare the efficacy of RPP and MZT products in the treatment of AGA. Methods: This retrospective study included 72 AGA patients treated with two PRP formulations and two MZT products, administered manually or with a gun injector. Hair parameters (hair thickness, hair density, and hair count) on frontal and vertex areas were measured before and after 6 months. Results: Over 6 months, trichoscopic parameters showed significant intragroup and intergroup variability. MZT1 and PRP2 groups exhibited statistically significant improvement in most parameters, while MZT2 significantly increased vertex hair density. Hair thickness changes differed significantly between PRP1 and PRP2 groups (unadjusted p value <0.001) and possibly between MZT1 and PRP1 groups (unadjusted p value = 0.049) in both regions. Discussion: Injections of PRP and MZT formulations can significantly enhance trichoscopic parameters in AGA patients within a 6-month period, but the extent of improvement varies among different PRP and MZT products.

Therapeutic Potential of Platelet-Rich Plasma in Fracture Healing: A Comprehensive Review.

Fracture healing is a dynamic process essential for the restoration of bone integrity and function. However, factors such as patient age, comorbidities, and the severity of the fracture can impede this process, leading to delayed healing or nonunion. Platelet-rich plasma (PRP) has emerged as a promising therapeutic option for enhancing fracture healing. PRP is an autologous blood product containing a concentrated mixture of platelets, growth factors, and cytokines known to promote tissue regeneration and repair. This comprehensive review provides an overview of the fracture healing process, emphasizing the importance of timely and efficient bone repair. We discuss the mechanisms underlying the purported efficacy of PRP in fracture healing, drawing upon both preclinical and clinical evidence. Preclinical studies in animal models have demonstrated the ability of PRP to accelerate fracture healing, stimulate osteogenesis, and enhance bone regeneration. Clinical studies have yielded mixed results, with some reporting positive outcomes in terms of accelerated healing and improved functional outcomes, while others have shown no significant benefits over standard treatments. Factors influencing the efficacy of PRP, such as timing of administration, PRP concentration, and patient-specific variables, are also examined. Furthermore, safety considerations and potential adverse effects associated with PRP therapy are discussed. Despite the promising preclinical findings, challenges remain in standardizing PRP formulations, optimizing administration protocols, and addressing unanswered questions regarding its long-term efficacy and safety. This review aims to provide insights into the therapeutic potential of PRP in fracture healing, informing future research directions and guiding clinical practice.

Not all platelet-rich plasma are created equal.

This review aims to elucidate potential variations in clinical outcomes resulting from the use of different types of platelet-rich plasma (PRPs) in reproductive medicine. It seeks to explore the reasons behind the diverse results reported in various studies and assess the general features distinguishing different PRP formulations. PRPs have found applications across diverse medical fields, generating controversy due to the variability in outcomes. The field of reproductive medicine, despite its limited published studies, is encountering a similar challenge as it integrates these treatments. The multitude of PRP product brands in the market, coupled with 'home-made' PRPs, poses a significant barrier to establishing a common protocol for the preparation of standardized PRP products. This impediment hinders widespread adoption by clinicians, particularly in endometrial or ovarian treatments. Drawing from evidence in other medical disciplines, this review endeavors to compile essential characteristics that PRPs must possess, aiming to mitigate the impact of variables affecting results in forthcoming studies.

Statistical Fragility of Randomized Controlled Trials Evaluating Platelet-Rich Plasma Use for Knee Osteoarthritis: A Systematic Review.

Numerous studies have been published on the use of platelet-rich plasma (PRP) for knee osteoarthritis (OA), with conflicting results. To determine the fragility index (FI) and fragility quotient (FQ) of randomized controlled trials (RCTs) that evaluated the use of PRP to treat knee OA. Systematic review. RCTs evaluating the efficacy of PRP injections for knee OA from 2000 to 2020 were included for analysis according to PRISMA guidelines. The FI was determined by calculating the number of outcome event reversals required to change the statistical significance. The associated FQ was determined by dividing the FI by the sample size. Our initial search resulted in 41,149 studies, of which 8 RCTs (678 patients, 72 outcome events) were included in the analysis. One study failed to report PRP formulation details, whereas 87.5% of studies reported using either leukocyte-rich or leukocyte-poor PRP. The platelet concentration was reported in 25% of the included trials. The overall FI of the 72 outcome events was 8.5. Accounting for sample size, the associated FQ was determined to be 0.14, suggesting that the reversal of 14% of outcome events was required to change outcome significance. There were 51 statistically significant outcomes, of which the FI and FQ were 12 and 0.164, respectively. Comprehensive fragility analysis suggested that the published literature evaluating the efficacy of PRP use for knee OA may lack statistical stability. We recommend the reporting of both an FI and FQ in addition to P value analysis to provide a clear and thorough understanding of the statistical integrity of studies reporting on PRP use for knee OA.

Cellular composition modifies the biological properties and stability of platelet rich plasma membranes for tissue engineering.

Scaffolds should provide structural support for tissue regeneration, allowing their gradual biodegradation and interacting with cells and bioactive molecules to promote remodeling. Thus, the scaffold's intrinsic properties affect cellular processes involved in tissue regeneration, including migration, proliferation, differentiation, and protein synthesis. In this sense, due to its biological effect and clinical potential, Platelet Rich Plasma (PRP) fibrin could be considered a successful scaffold. Given the high variability in commercial PRPs formulations, this research focused on assessing the influence of cellular composition on fibrin membrane stability and remodeling cell activity. The stability and biological effect were evaluated at different time points via D-dimer, type I collagen and elastase quantification in culture media conditioned by Plasma Rich in Growth Factors - Fraction 1 (PRGF-F1), Plasma Rich in Growth Factors - Whole Plasma (PRGF-WP) and Leukocyte-rich Platelet Rich Plasma (L-PRP) membranes, and by gingival fibroblast cells seeded on them, respectively. Ultrastructure of PRP membranes was also evaluated. Histological analyses were performed after 5 and 18 days. Additionally, the effect of fibrin membranes on cell proliferation was determined. According to the results, L-PRP fibrin membranes degradation was complete at the end of the study, while PRGF membranes remained practically unchanged. Considering fibroblast behavior, PRGF membranes, in contrast to L-PRP ones, promoted extracellular matrix biosynthesis at the same time as fibrinolysis and enhanced cell proliferation. In conclusion, leukocytes in PRP fibrin membranes drastically reduce scaffold stability and induce behavioral changes in fibroblasts by reducing their proliferation rate and remodeling ability.

Platelet Rich Plasma : A Boon To Periodontics

Platelet-rich plasma (PRP), a recently developed autologous cellular therapy, has the potential to perform new functions in an array of regenerative pharmacological treatment plans. Platelet growth factors (PGFs) promote the three stages of the wound recovery and repair cascade, which is the cornerstone of PRP therapy (inflammation, proliferation, remodelling). In vitro, in vivo, and animal experiments were used to test a wide range of PRP formulations. Yet, because it is difficult to apply the findings and technique recommendations from non-clinical studies to human clinical treatment protocols, recommendations from in vitro and animal research frequently result in various clinical manifestations. In this study, we addressed recent advancements in PRP production and composition, applications in periodontics, and PRP mechanisms relating to tissue inflammation and angiogenesis.

Platelet Rich Plasma Effects on Diabetic Foot Ulcers - A Review

Abstract: Utilizing platelet rich plasma, one of the newest autologous cellular therapies, as an adjuvant therapy in a regenerative medicine management, can be very beneficial. Patients with complications like osteoarthritis, spinal disorders and musculoskeletal problems still facing global lacking in the area of tissue repair strategies. Along with this another major complication associated is with diabetic patients - the development of diabetic foot ulcers that predisposes to limb amputation. To advance the healing process and prevent the patients from progressing towards amputations. Besides many other approaches used. Platelet Rich Plasma (PRP) therapy is attaining momentum, which is composed of platelet growth factors that assist the wound healing cascade – inflammation, proliferation and remodeling. It may occur because of provision of vital growth factors necessary for healing. Currently, variety of PRP formulations have been assessed. The article intends to evaluate the PRP effectiveness for managing diabetic ulcers.

Platelet-Rich Plasma for Intra-articular Injections: Preclinical and Clinical Evidence.

The use of platelet-rich plasma (PRP) has been supported by encouraging data from in vitro and preclinical in vivo studies, both in terms of safety and efficacy. This led to the wide use of PRP injections in the clinical practice, with promising results especially as a minimally invasive treatment for cartilage degeneration and osteoarthritis (OA). While many controversies remain on the best PRP formulation, the overall available clinical studies support the benefits of PRP, with functional improvement and reduction of pain-related symptoms up to 12months, especially in young patients and early OA stages.

Current State of Platelet-Rich Plasma and Cell-Based Therapies for the Treatment of Osteoarthritis and Tendon and Ligament Injuries.

Orthobiologics encompass numerous substances that are naturally found in the human body including platelet-rich plasma (PRP), isolated growth factors, and cell therapy approaches to theoretically optimize and improve the healing of cartilage, fractures, and injured muscles, tendons, and ligaments. PRP is an autologous derivative of whole blood generated by centrifugation and is perhaps the most widely used orthobiologic treatment modality. Despite a vast amount of literature on its use in osteoarthritis as well as in tendon and ligament pathology, clinical efficacy results remain mixed, partly as a result of insufficient reporting of experimental details or exact compositions of PRP formulations used. Mesenchymal stromal cells (MSCs) can be isolated from a variety of tissues, with the most common being bone marrow aspirate concentrate. Similar to PRP, clinical results in orthopaedics with MSCs have been highly variable, with the quality and concentration of MSCs being highly contingent on the site of procurement and the techniques of harvesting and preparation. Advances in novel orthobiologics, therapeutic targets, and customized orthobiologic therapy will undoubtedly continue to burgeon, with some early promising results from studies targeting fibrosis and senescence.

Leukocyte-Rich Platelet-Rich Plasma Has Better Stimulating Effects on Tenocyte Proliferation Compared With Leukocyte-Poor Platelet-Rich Plasma.

Background:Rotator cuff (RC) tendinopathy is one of the most common causes of shoulder pain. Platelet-rich plasma (PRP) has been frequently used in clinical scenarios, but its efficacy remains inconsistent.Purpose:To investigate the different responses of human tenocytes from torn RCs to leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) in a 2-chamber coculture device.Study Design:Controlled laboratory study.Methods:PRP was prepared using different platelet and leukocyte concentrations according to 5 groups: (1) LR-PRP with 5000 platelets/µL, (2) LR-PRP with 10,000 platelets/µL, (3) LP-PRP with 5000 platelets/µL, (4) LP-PRP with 10,000 platelets/µL, and (5) control with only culture medium supplementation and without PRP stimulation. Platelet-derived growth factor–AB (PDGF-AB) and transforming growth factor–β1 (TGF-β1) were measured in LR-PRP and LP-PRP via enzyme-linked immunosorbent assay. Microscopy, water-soluble tetrazolium salt assay, and quantitative real-time polymerase chain reaction were used to investigate the morphology, proliferation, and gene expression of RC tenocytes exposed to different PRP formulations. Data were collected from at least 3 independent measurements. The results were analyzed via 1-way analysis of variance, followed by the post hoc Bonferroni test.Results:The ratio of leukocytes to 5000 platelets/µL was 29.5 times higher in LR-PRP than in LP-PRP (P < .05). In the 5000 platelets/µL groups, the levels of TGF-β1 and PDGF-AB were both significantly higher in LR-PRP versus LP-PRP (TGF-β1: 367.0 ± 16.5 vs 308.6 ± 30.3 pg/mL, respectively [P = .043]; PDGF-AB: 172.1 ± 1.8 vs 94.1 ± 4.2 pg/mL, respectively [P < .001]). Compared with the control group, RC tenocyte proliferation was 1.42 ± 0.01 and 1.41 ± 0.03 times higher in the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL, respectively (P < .05). The expression of tenocyte-related genes was higher in tenocytes cultured in LR-PRP.Conclusion:Both the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL induced more growth factor release and increased RC tenocyte proliferation than did the LP-PRP groups.Clinical Relevance:In RC repair, LR-PRP may be better than LP-PRP for increasing the proliferation of tenocytes.

Unraveling the Signaling Secretome of Platelet-Rich Plasma: Towards a Better Understanding of Its Therapeutic Potential in Knee Osteoarthritis.

Platelets and their secretory products play an important role in determining the balance between tissue repair and tissue damage. To obtain novel insights into the molecular composition of platelet-rich plasma (PRP) and contextualize them in knee osteoarthritis (OA), two different plasma formulations, namely PRP and platelet-poor plasma (PPP), were prepared from six healthy donors following a biobank-automated protocol. Inter-donor differences were analyzed, and pools were created before performing multiplexing protein arrays. In addition, PRP and PPP were prepared from six patients following our in-house protocols. Supernatants from PRP and PPP were harvested one hour after calcium chloride activation. Multiplexing protein arrays were performed in parallel for all plasma formulations. Results were normalized to fold change in relation to PPP and examined using Ingenuity Pathway Analysis Software. Bioinformatic predictions showed that PRPs constitute a signaling system with interrelated networks of inflammatory and angiogenic proteins, including but not limited to interleukin-6 and -8 (IL-6, IL-8), insulin like growth factor 1 (IGF-1), transforming growth factor beta, (TGF-b), and vascular endothelial growth factor (VEGF) signaling, underlying biological actions. Predictions of canonical systems activated with PRP molecules include various inflammatory pathways, including high-mobility group box protein (HMGB1) and interleukin 17 (IL-17) signaling, neuroinflammation, and nuclear factor-kappa b (NF-κB) pathways. Eventually, according to these predictions and OA evolving knowledge, selected PRP formulations should be tailored to modulate different inflammatory phenotypes, i.e., meta-inflammation, inflame-aging or posttraumatic inflammatory osteoarthritis. However, further research to discriminate the peculiarities of autologous versus allogeneic formulations and their effects on the various OA inflammatory phenotypes is needed to foster PRPs.

The Effect of a Single Freeze-Thaw Cycle on Matrix Metalloproteinases in Different Human Platelet-Rich Plasma Formulations.

Storing platelet-rich plasma (PRP) for future use is a compelling approach, presuming the retention of biological properties is maintained. However, certain factors in PRP preparations have deleterious effects for the treatment of certain musculoskeletal conditions. The purpose of this study was to measure and compare matrix metalloproteinase protein (MMP) concentrations between fresh and freeze-thawed leukocyte-rich PRP (LR-PRP) inactivated (LR-I) and activated (LR-A) preparations, and leukocyte-poor PRP (LP-PRP) inactivated (LP-I) and activated (LP-A) preparations. A volume of 60 mL of whole blood was drawn from 19 healthy donors. LP-I and LR-I samples were processed using a manual extraction and centrifugation methodology. LP-A and LR-A products were activated with 10% CaCl2 and recombinant thrombin. Blood fractions were either immediately assayed and analyzed or stored at −80 °C for 24, 72 and 160 h. Multiplex immunoassay was used to measure MMP-1, MMP-2, MMP-3, MMP-9, MMP-10, and MMP-12. MMP-1 concentrations increased in LR-A (p < 0.05) and MMP-9 significantly increased in LR-I (p < 0.05), while MMP-2 significantly decreased in LR-I (p < 0.05) and MMP-3 concentrations significantly decreased in LR-A (p < 0.05). MMP-12 concentrations also significantly decreased in LR-I (p < 0.05) from baseline concentrations. There were no significant differences between LP-A and LP-I preparations and MMP concentrations. MMP-10 concentrations in all PRP samples compared to each freezing time point were also not significantly different. MMPs regulate components of the extracellular matrix (ECM) in the remodeling phase of musculoskeletal injury. In this study, we observed a significant increase and decrease in MMP concentrations in response to a single freeze–thaw cycle in inactivated PRP and activated PRP preparations. This evidence contributes to the growing body of literature on the optimization of PRP preparation and storage strategies prior to delivery. Our findings suggest that specific PRP preparations after a single freeze–thaw may be more advantageous for certain musculoskeletal applications based on the presence of MMP concentrations.

Platelet-rich plasma injections induce disease-modifying effects in the treatment of osteoarthritisin animal models.

The mechanisms of action and disease-modifying potential of platelet-rich plasma (PRP) injection for osteoarthritis (OA) treatment are still not fully established. The aim of this systematic review of preclinical evidence was to determine if PRP injections can induce disease-modifying effects in OA joints. A systematic review was performed on animal studies evaluating intra-articular PRP injections as treatment for OA joints. A synthesis of the results was performed investigating the disease-modifying effects of PRP by evaluating studies that compared PRP with OA controls or other injectable products, different PRP formulations or injection intervals, and the combination of PRP with other products. The risk of bias was assessed according to the SYRCLE's tool. Forty-four articles were included, for a total of 1251 animals. The publication trend remarkably increased over time. PRP injections showed clinical effects in 80% and disease-modifying effects in 68% of the studies, attenuating cartilage damage progression and reducing synovial inflammation, coupled with changes in biomarker levels. Evidence is limited on the best PRP formulation, injection intervals, and synergistic effect with other injectables. The risk of bias was low in 40%, unclear in 56%, and high in 4% of items. Intra-articular PRP injections showed disease-modifying effects in most studies, both at the cartilage and synovial level. These findings in animal OA models can play a crucial role in understanding mechanism of action and structural effects of this biological approach. Nevertheless, the overall low quality of the published studies warrants further preclinical studies to confirm the positive findings, as well as high-level human trials to demonstrate if these results translate into disease-modifying effects when PRP is used in the clinical practice to treat OA. Level II.

The Efficacy of Platelet-Rich Plasma for Improving Pain and Function in Lateral Epicondylitis: A Systematic Review and Meta-analysis with Risk-of-Bias Assessment

To assess the efficacy of platelet-rich plasma (PRP) for lateral epicondylitis and evaluate its impact on pain and functional outcomes.This study followed Preferred Reporting Items and Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search was conducted in September 2019 and repeated in April 2020 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Baseline and 3-, 6-, and 12-month data were extracted for visual analog scale (VAS), Disabilities of the Arm, Shoulder, and Hand (DASH), and modified Mayo Clinic performance index for the elbow (MAYO) scores. Only level 1 studies with patients who had not undergone surgery were included. Outcomes data, study design, demographic variables, PRP formulation, and comparator treatments were recorded. Statistical analyses of pooled weighted mean differences (WMDs) were performed and compared with estimated minimal clinically important difference (MCID) values. The Coleman Methodology Score (CMS) was used to assess methodological quality, and the Cochrane risk-of-bias assessment was performed.This review included 16 level I studies, 9 of which (581 total patients, 281 receiving single injections of PRP) were quantitatively analyzed. The average age was 41.5 years, 56.8% of patients were female, and mean follow-up was 7.5 months. The mean CMS was 78.94 ± 12.74 (range 59 to 97), and 5 of 16 studies were at low risk for bias. Patients who received PRP had significantly improved VAS scores at 3 months (WMD -0.85; 95% confidence interval [CI] -1.03, -0.66; P < .01) and 6 months (WMD -0.74; 95% CI -0.98, -0.50; P < .01) compared with those who received autologous whole blood, though MAYO scores were statistically equivalent. Comparing PRP to corticosteroids, VAS and DASH scores were not significantly different at 3 months, although PRP was superior at 6 months for VAS (WMD -1.70; 95% CI -2.65, -0.75; P < .01) and DASH (WMD -6.23; 95% CI -10.78, -1.69; P < .01). Most differences in VAS and DASH scores exceeded the 5% absolute difference estimate for their respective MCIDs but fell short of the 10% estimate.Considering the small number of comparable studies, lack of quantification of specific PRP content, considerable heterogeneity between randomized control trials, and most effect sizes being equivocal within the framework of 2 estimated MCID values, the authors can neither scientifically support nor discourage the usage of PRP for lateral epicondylitis despite finding statistically significant improvements in pain and functional outcomes.I, prognostic.

New Trends in Injection-Based Therapy for Thumb-Base Osteoarthritis: Where Are We and where Are We Going?

Thumb-base osteoarthritis (TBOA) is a common condition, mostly affecting post-menopausal women, often inducing a significant impact on quality of life and hand functionality. Despite its high prevalence and disability, the therapeutic options in TBOA are still limited and few have been investigated. Among the pharmacological strategies for TBOA management, it would be worthwhile to mention the injection-based therapy. Unfortunately, its efficacy is still the subject of debate. Indeed, the 2018 update of the European League Against Rheumatism (EULAR) recommendations for the management of hand osteoarthritis (OA) stated that intra-articular (IA) injections of glucocorticoids should not generally be used, but may be considered in patients with painful interphalangeal joints, without any specific mention to the TBOA localization and to other widely used injections agents, such as hyaluronic acid (HA) and platelet-rich plasma (PRP). Even American College of Rheumatology (ACR) experts conditionally recommended against IA HA injections in patients with TBOA, while they conditionally encouraged IA glucocorticoids. However, the recommendations from international scientific societies don’t often reflect the clinical practice of physicians who routinely take care of TBOA patients; indeed, corticosteroid injections are a mainstay of therapy in OA, especially for patients with pain refractory to oral treatments and HA is considered as a safe and effective treatment. The discrepancy with the literature data is due to the great heterogeneity of the clinical trials published in this field: indeed, the studies differ for methodology and protocol design, outcome measures, treatment (different formulations of HA, steroids, PRP, and schedules) and times of follow-up. For these reasons, the current review will provide deep insight into the injection-based therapy for TBOA, with particular attention to the different employed agents, the variety of the schedule treatments, the most common injection techniques, and the obtained results in terms of efficacy and safety. In depth, we will discuss the available literature on corticosteroids and HA injections for TBOA and the emerging role of PRP and other injection agents for this condition. We will consider in our analysis not only randomized controlled trials (RCTs) but also recent pilot or retrospective studies trying to step forward to identify satisfactory management strategies for TBOA.

CXCL5 Cytokine Is a Major Factor in Platelet-Rich Plasma's Preservation of Erectile Function in Rats After Bilateral Cavernous Nerve Injury

BackgroundThe neuro-protective and tissue-protective properties of platelet-rich plasma (PRP) have been demonstrated through treating bilateral cavernous nerve (CN) injury in rats, although the underlying mechanisms have not been fully clarified. AimTo determine factors released from PRP and explore their role in mediating preservation of erectile function (EF) in a rat model of CN injury. MethodsMale Sprague-Dawley rats (aged 10 weeks) were used in this study. 6 rats were used to obtain blood for PRP and whole plasma preparation. We probed samples using a cytokine antibody array and performed enzyme-linked immunosorbent assay (ELISA). We determined the expression patterns of C-X-C motif chemokine ligand 5 (CXCL5) and receptors in the major pelvic ganglion (MPG) and corpus cavernosum via immunostaining. 32 rats were divided into 4 groups based on the type of injection received: (i) sham, (ii) vehicle, (iii) 400 μL of PRP, and (iv) 30 ng/kg of CXCL5. Groups 2–4 were subjected to bilateral CN crush (BCNC) injury. 4 weeks later, EF was assessed by CN electrostimulation, and CNs and penile tissue were collected for histological analysis. OutcomeCytokine antibody array, ELISA, erectile response, and immunofluorescence staining readings. ResultsThe PRP contained high levels of CXCL5. MPG neurons expressed CXCL5 and CXCR2. PRP intracavernous injection stabilized CXCR2 and increased CXCL5 expression in the MPG after BCNC, thus enhancing neuroprotection. CXCL5 injection improved BCNC-induced erectile dysfunction by preventing smooth muscle atrophy. Clinical ImplicationsThe therapeutic efficacy of PRP in CN injury–induced erectile dysfunction may arise from the synergy among multiple biomolecules. Our study serves as a basis for future studies on PRP formulation to provide safe and effective medications for the maintenance of EF after radical prostatectomy in patients with prostate cancer. Strengths & LimitationsA strength of our study is that our model was able to isolate the role of cytokines, specifically CXCL5, as part of the mechanism responsible for PRP's protective properties. However, the rat cytokine array provided limited experimental targets. The rats used were not at the age corresponding to prostate cancer patients in clinical settings. Our study did not explore CXCL5 blocking in the PRP group. Finally, the main protein quantification results by western blotting were hampered because of small tissue samples. ConclusionsThis study provides evidence for the role of CXCL5 and CXCR2 as mediators of PRP effects in the preservation of EF after CN injury.Wu YN, Liao CH, Chen KC, et al. CXCL5 Cytokine Is a Major Factor in Platelet-Rich Plasma's Preservation of Erectile Function in Rats After Bilateral Cavernous Nerve Injury. J Sex Med 2021;18:698–710.

Platelet-Rich Plasma Combined with Hyaluronic Acid versus Leucocyte and Platelet-Rich Plasma in the Conservative Treatment of Knee Osteoarthritis. A Retrospective Study.

Background and objectives: Knee osteoarthritis (KO) is one of the most common joint diseases, determining knee pain and reduction of mobility, with a negative effect on quality of life. Intra-articular injections of different formulations of platelet-rich plasma (PRP) are an increasingly common non-surgical treatment for KO. Recently, in order to combine the anti-inflammatory effect of platelet rich plasma and the viscosupplementation effect of hyaluronic acid, a formulation of PRP combined with hyaluronic acid (PRP + HA) has been proposed. The purpose of this study is to retrospectively compare the effectiveness of plasma with high concentration of platelets and leukocytes (L-PRP) with PRP + HA in patients with mild to moderate (Kellgren–Lawrence scale II-III grade) KO. Materials and Methods: Among the 51 patients included, 28 have been treated with L-PRP, while 23 with PRP + HA. A retrospective evaluation at baseline (T0), after 3 months (T1) and 1 year (T2) has been performed. The outcome analyzed are the Knee Society Score (KSS), the Visuo Analogic Scale (VAS) (at T0, T1, and T2) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) (T0 and T2). We evaluated change in mean scores within and between groups among different time points using repeated measures ANCOVA. Results: Although the two treatments have been both effective in reducing VAS, the group treated with PRP + HA showed a significantly lower KSS. Conclusions: Our results show that the use of both treatments may help to reduce pain in patients with mild to moderate KO. PRP + HA showed better results in improving knee mobility and function. These results should be considered only preliminary: Further research is needed to completely describe the clinical effectiveness of these formulations.

Platelet-rich plasma (PRP) in osteoarthritis (OA) knee: Correct dose critical for long term clinical efficacy

Despite encouraging results reported with regards to Platelet-rich plasma (PRP) application in osteoarthritis (OA) knee, still critical issues like conclusive structural evidence of its efficacy, standard dose and good manual method of preparation to obtain high yield remains unanswered. Present study is an attempt to optimise the dose and concentration of therapeutic PRP and its correlation with structural, physiologic efficacy with a new manual method of PRP preparation. A total of one hundred and fifty patients were randomized to receive either PRP (10 billion platelets) or hyaluronic acid (HA; 4 ml; 75 patients in each group) and followed up till 1 year. An addition of filtration step with 1 µm filter in manual PRP processing improved platelet recovery upto 90%. Significant improvements in WOMAC (51.94 ± 7.35 vs. 57.33 ± 8.92; P < 0.001), IKDC scores (62.8 ± 6.24 vs 52.7 ± 6.39; P < 0.001), 6-min pain free walking distance (+ 120 vs. + 4; P < 0.001) persisted in PRP compared to HA group at 1 year. Significant decline IL-6 and TNF-α levels observed in PRP group (P < 0.05) compared to HA at 1 month. Study demonstrated that an absolute count of 10 billion platelets is crucial in a PRP formulation to have long sustained chondroprotective effect upto one year in moderate knee OA.

Systematic Review and Meta-Analysis of Nonoperative Platelet-Rich Plasma Shoulder Injections for Rotator Cuff Pathology.

Platelet-rich plasma (PRP) injections have been introduced to augment the recovery of patients with shoulder pathology. Although multiple studies have been published, no large-scale trials or meta-analyses have assessed the efficacy of nonoperative shoulder PRP injection. To assess the efficacy of nonoperative PRP shoulder injection in rotator cuff pathology for pain as measured by the visual analog scale (VAS) and range of motion (ROM). Two authors independently screened the Medline and Cochrane databases to include prospective studies that reported VAS and ROM outcomes for nonoperative shoulder PRP injections for rotator cuff pathology. Study quality was assessed using the revised Cochrane Collaboration risk-of-bias tool and modified Downs and Black checklist. Subsequent meta-analysis was performed to determine the effect of nonoperative PRP injections on pain and ROM 3 to 12 months after intervention. Six studies met systematic review criteria. The included studies used different PRP formulations (concentration, leukocyte count), injection protocols (approach, injection number), and varied study designs. Three studies concluded that PRP provided no significant benefit for pain and ROM when compared to physical therapy. Within-group meta-analysis of six fairly heterogeneous studies (I2 77.8%) demonstrated a statistically significant (P< .001) improvement in pain 3 to 12 months after PRP injection. Within-group meta-analysis for four studies for shoulder flexion and abduction was found to be too heterogeneous to derive meaningful results. There is a limited quantity of high-quality studies that assess the efficacy of nonoperative PRP shoulder injection for pain and ROM. Systematic review of PRP injections did not demonstrate an improvement in pain or ROM compared to physical therapy. Although within-group meta-analysis of nonoperative PRP statistically showed that nonoperative PRP improved pain, the lack of adequate negative controls precludes the ability to conclude whether improvements were due to natural recovery or nonoperative PRP.

Comment on moving toward targeting the right phenotype with the right platelet-rich plasma formulation for knee osteoarthritis.

Comment on moving toward targeting the right phenotype with the right platelet-rich plasma formulation for knee osteoarthritis.